older class link (2006)
-- not completely about CAs, but the "xtoys" applications are really
nifty if you can figure out how to run them (X windows -- those were the
days!)
older class link (2000)
-- most of the links are bogus, but a good example (and commentary) of
a C-code development of a CA
Also check out the examples/jitter-examples/3rd_Party/Cellular.maxpat
and examples/jitter-examples/other/Wolframatic/Wolframatic.maxpat
Max/MSP example patchers that come with the distribution if you
have it.